BK polyomavirus-pathogen, paradigm and puzzle

Protocolized polyoma BK viral load monitoring and high-dose immunoglobulin treatment in children after kidney transplant

Background

BKPyV virus nephropathy (BKPyVAN) is diagnosed in 5%-16% of pediatric renal transplant recipients (PRTR) and preceded by BKPyV-viruria and DNAemia. Despite the risk of irreversible transplant damage associated with BKPyVAN, evidence-based consensus guidelines for BKPyVAN prevention are still lacking. In this retrospective study, we examined the safety and efficacy of high-dose intravenous immunoglobulin (HD-IVIG) therapy for prevention of BKPyVAN in PRTR with significant BKPyV-viruria/DNAemia.

Methods

Between January 2013 and December 2022, all PRTR under our care underwent routine urine and blood testing for BKPyV viral load, using specific polymerase chain reaction (PCR). BKPyV DNAemia, with <103 copies/mL, with BKPyV viruria <107 copies/mL, with no evidence of BKPyVAN, were managed with 50% dose reduction of mycophenolate mofetil (MMF). Patients showing no decline in BKPyV viral load within two months of MMF dose reduction were managed with HD-IVIG (2 g/kg).

Results

Seventy patients were recruited during a ten-year period and 31/70 patients (44%) demonstrated significant post-transplantation BKPyV-viruria/DNAemia, while 13/31 (42%) patients were unresponsive to MMF dose reduction, and were administered HD-IVIG. Of these, 12/13 (92%) patients achieved BKPyV viral clearance within six months from completion of HD-IVIG therapy and 1/13 patient (8%) was unresponsive to HD-IVIG therapy, showing increased BKPyV viral load. There were no major adverse events associated with HD-IVIG, and none of our patients developed BKPyVAN during the study period.

Conclusions

Prophylactic HD-IVIG therapy in PRTR with significant BKPyV-viruria/DNAemia unresponsive to MMF dose reduction is safe and might be effective in preventing BKPyVAN. Our findings remain to be established by large-scale prospective studies.

Exploring potential targets of HPV&BC based on network pharmacology and urine proteomics

BACKGROUND

Bladder cancer (BC) caused by Human papillomavirus (HPV) infection remains a complex public health problem in developing countries. Although the HPV vaccine effectively prevents HPV infection, it does not benefit patients with BC who already have HPV.

METHODS

Firstly, the differential genes of HPV-related BC patients were screened by transcriptomics, and then the prognostic and clinical characteristics of the differential genes were analyzed to screen out the valuable protein signatures. Furthermore, the compound components and targets of Astragali Radix (AR) were analyzed by network pharmacology, and the intersection targets of drug components and HPV_BC were screened out for pathway analysis. In addition, the binding ability of the compound to the Astragali-HPV_BC target was verified by molecular docking and virtual simulation. Finally, to identify potential targets in BC patients through urine proteomics and in vitro experiments.

RESULTS

Eleven HPV_BC-related protein signatures were screened out, among which high expression of EGFR, CTNNB1, MYC, GSTM1, MMP9, CXCR4, NOTCH1, JUN, CXCL12, and KRT14 had a poor prognosis, while low expression of CASP3 had a poor prognosis. In the analysis of clinical characteristics, it was found that high-risk scores, EGFR, MMP9, CXCR4, JUN, and CXCL12 tended to have higher T stage, pathological stage, and grade. Pharmacological and molecular docking analysis identified a natural component of AR (Quercetin) and it corresponding core targets (EGFR). The OB of the natural component was 46.43, and the DL was 0.28, respectively. In addition, EGFR-Quercetin has high affinity. Urine proteomics and RT-PCR showed that EGFR was expressed explicitly in BC patients. Mechanism analysis revealed that AR component targets might affect HPV_BC patients through Proteoglycans in the cancer pathway.

CONCLUSION

AR can target EGFR through its active component (Quercetin), and has a therapeutic effect on HPV_BC patients.

A case of acute kidney injury due to native kidney BK polyomavirus-associated nephropathy in a human T-lymphotropic virus type 1 carrier

BACKGROUND

BK polyomavirus-associated nephropathy (BKPyVAN) has become a major cause of kidney dysfunction and graft loss in kidney transplant recipients. On rare occasion, polyomavirus has also been known to affect native kidneys of immunocompromised individuals. Only a small number of opportunistic infections have been reported in the carrier phase of human T-lymphotropic virus type 1 (HTLV-1). This is the first reported case of BKPyVAN in native kidneys of an HTLV-1 carrier.

CASE PRESENTATION

A 61-year-old man was referred to our hospital from a primary care physician for work-up and treatment of pneumonia. He was diagnosed with Pneumocystis pneumonia and identified as a HTLV-1 carrier who had not yet developed adult T-cell leukemia (ATL). The pneumonia was successfully treated with sulfamethoxazole-trimethoprim. He had never been diagnosed with any kind of kidney dysfunction. Laboratory investigations showed a serum creatinine of 5.3 mg/dL, and urinary sediment showed cells with nuclear enlargement and inclusion bodies suggesting viral infection. The urinary Papanicolaou stain showed inclusions in swollen, ground-glass nuclei, typical of "decoy cells". Renal biopsy showed degeneration of tubules with epithelial enlargement, vacuolar degeneration, nuclear inclusion bodies, and detachment from the tubular basement membrane. Tubular nuclei showed positive staining positive for simian virus 40 large-T antigen. Polymerase chain reaction tests for BK polyomavirus DNA of both urine and plasma were positive. These findings confirmed a diagnosis of BKPyVAN. Intravenous immunoglobulin therapy did not improve renal function, necessitating maintenance hemodialysis therapy.

CONCLUSIONS

BKPyVAN should be considered when acute kidney injury occurs with opportunistic infection. HTLV-1 carriers can develop opportunistic infections even before the onset of ATL.

BK polyomavirus: latency, reactivation, diseases and tumorigenesis

The identification of the first human polyomavirus BK (BKV) has been over half century, The previous epidemiological and phylogenetic studies suggest that BKV prevailed and co-evolved with humans, leading to high seroprevalence all over the world. In general, BKV stays latent and symptomless reactivation in healthy individuals. BKV has been mainly interlinked with BKV-associated nephropathy (BKVAN) in kidney-transplant recipients and hemorrhagic cystitis (HC) in hematopoietic stem cell transplant recipients (HSCTRs). However, the mechanisms underlying BKV latency and reactivation are not fully understood and lack of extensive debate. As Merkel cell polyomavirus (MCV) was identified as a pathogenic agent of malignant cutaneous cancer Merkel cell carcinoma (MCC) since 2008, linking BKV to tumorigenesis of urologic tumors raised concerns in the scientific community. In this review, we mainly focus on advances of mechanisms of BKV latency and reactivation, and BKV-associated diseases or tumorigenesis with systematical review of formerly published papers following the PRISMA guidelines. The potential tumorigenesis of BKV in two major types of cancers, head and neck cancer and urologic cancer, was systematically updated and discussed in depth. Besides, BKV may also play an infectious role contributing to HIV-associated salivary gland disease (HIVSGD) presentation. As more evidence indicates the key role of BKV in potential tumorigenesis, it is important to pay more attention on its etiology and pathogenicity in vitro and in vivo.

Rapid Resolution of Life-Threatening Hypertriglyceridemia after Evinacumab Administration in a Pediatric HSCT Recipient: A Case Report

Evinacumab, a human monoclonal antibody against angiopoietin-like protein 3 (ANGPTL3), has recently been approved by the U.S. Food and Drug Administration as an add-on therapy for homozygous familial hypercholesterolemia (HoFH) in patients of 12 years and older. Its role as a triglyceride-lowering drug is also emerging in the literature. However, it has not been approved for this indication yet, neither in the adult nor in the pediatric population. We describe the case of a 10-year-old boy who underwent an allogeneic hematopoietic stem cell transplant for acute lymphoblastic leukemia complicated by chronic graft-versus-host disease (GVHD) and presented life-threatening refractory hypertriglyceridemia due to the concomitant use of ruxolitinib and sirolimus. After the failure of the insulin treatment and due to the technical impossibility of performing lipid apheresis, the child underwent evinacumab treatment, obtaining a dramatic rapid reduction in triglyceride and cholesterol levels. This is the first report of a pediatric patient younger than 12 years in Europe receiving evinacumab to treat severe hypertriglyceridemia. The therapy with angiopoietin-like proteins inhibitors has been effective, safe, and well-tolerated in our patient, suggesting that evinacumab may be used in the pediatric population when other therapeutic strategies are ineffective or contraindicated.

How to maximize graft survival

PURPOSE OF REVIEW

Kidney transplant failure results in significant patient morbidity and mortality, increased financial burden and exacerbates the organ shortage faced by kidney transplant candidates. The different strategies to maximize graft survival in kidney transplant recipients is presented in this review.

RECENT FINDINGS

Maximizing kidney graft survival requires optimizing immunosuppression, preventing and managing recurrent disease and using general chronic kidney disease strategies to slow allograft injury. Herein, we review: 1) strategies to tailor immunosuppression to the individual patient to avoid over and underimmunosuppression, and avoid immunosuppression-related drug toxicities, 2) latest findings in the following recurrent diseases: focal segmental glomerulosclerosis, membranous nephropathy, complement-mediated kidney disease and monoclonal gammopathy of renal significance, and, 3) approaches to slow allograft injury including BP control, and the use of antiproteinuric agents and SGLT-2 inhibitors.

SUMMARY

The last two decades has seen significant improvement in allograft outcomes resulting from advances in immunosuppression. With the federal government's renewed focus on kidney disease and transplantation, and recent advances in biomarkers, genetic testing, big data analytics and machine learning, we hope to see further outcome improvements in the next decade.

Value and limitations of sonography in kidney transplant recipients with special attention to the resistive index - An update

Kidney transplantation has become the standard treatment for end-stage renal disease. Even though the success rates are high, early and late post-transplant complications remain a major clinical problem due to the risk of graft failure. Therefore, it is of highest interest to early diagnose post-transplant complications. Ultrasound with color coded Duplex analysis plays a crucial role in imaging mechanical and vascular complications. In this article, we give an update of the visualizable complications in kidney transplant recipients and discuss the value of resistive index (RI) measurement with its limitations in allograft rejection.

Human genes with relative synonymous codon usage analogous to that of polyomaviruses are involved in the mechanism of polyomavirus nephropathy

Human polyomaviruses (HPyVs) can cause serious and deleterious infections in human. Yet, the molecular mechanism underlying these infections, particularly in polyomavirus nephropathy (PVAN), is not well-defined. In the present study, we aimed to identify human genes with codon usage bias (CUB) similar to that of HPyV genes and explore their potential involvement in the pathogenesis of PVAN. The relative synonymous codon usage (RSCU) values of genes of HPyVs and those of human genes were computed and used for Pearson correlation analysis. The involvement of the identified correlation genes in PVAN was analyzed by validating their differential expression in publicly available transcriptomics data. Functional enrichment was performed to uncover the role of sets of genes. The RSCU analysis indicated that the A- and T-ending codons are preferentially used in HPyV genes. In total, 5400 human genes were correlated to the HPyV genes. The protein-protein interaction (PPI) network indicated strong interactions between these proteins. Gene expression analysis indicated that 229 of these genes were consistently and differentially expressed between normal kidney tissues and kidney tissues from PVAN patients. Functional enrichment analysis indicated that these genes were involved in biological processes related to transcription and in pathways related to protein ubiquitination pathway, apoptosis, cellular response to stress, inflammation and immune system. The identified genes may serve as diagnostic biomarkers and potential therapeutic targets for HPyV associated diseases, especially PVAN.

A bibliometric analysis of top-cited journal articles in interstitial cystitis and bladder pain syndrome

INTRODUCTION AND HYPOTHESIS

To identify and compare the top-cited articles from all indexed journals and urology-nephrology and obstetrics-gynecology journals in the Institute for Scientific Information Web of Science's Citation Index Expanded on interstitial cystitis and bladder pain syndrome (IC/BPS).

METHODS

Cross-sectional bibliometric analysis of top-cited articles in Web of Science^TM (WoS) from 1900-2022. The articles were retrieved by the MeSH terms from NCBI. The characteristics of top 100 cited articles from all indexed journals and specialized journals were evaluated.

RESULTS

A total of 5547 articles were collected from 1115 journals, in which 3225 articles were from 141 urological and gynecological specialized journals. The USA and the UK were the top two origins for articles on interstitial cystitis. The articles from non-specialized journals were more frequently cited than those from specialized journals (median [IQR], 221.5 [189.8-313.5] vs 131.0 [126.0-142.8], P < 0.0001). The citation number per year showed similar results (median [IQR], 239.9 [194.5-311.8] vs 132.0 [126.7-140.5], P < 0.0001). There were many more open-access articles in non-specialized than specialized journals (P = 0.0018).

CONCLUSIONS

The current study initially queried the articles published on WoS on IC/BPS by the number of citations to identify the differences between two journal categories. The characteristics and trends of research were analyzed by citations to provide insights into the current research status and future direction.

BK virus nephropathy in a heart transplant recipient

BK virus nephropathy in kidney transplantation is widely recognized as an important cause of graft dysfunction and loss. In the case of transplants of organs other than kidney, BK virus nephropathy in native kidneys has been recognized as a cause of chronic kidney disease, which is related with immunosuppression; however, the diagnosis is usually late because the renal dysfunction is attributed to other causes, such as toxicity by anticalcineurinic drugs, interstitial nephritis due to medications, hemodynamic changes, diabetes, hypertension, etc. We report a case of BK virus nephropathy in a patient who underwent heart transplantation due to peripartum cardiomyopathy. The kidney biopsy reported active chronic tubulointerstitial nephritis associated with late stage polyomavirus nephritis and the blood viral load for BK virus was positive (logarithm 4.5). The immunosuppressive treatment was reduced, and after two years of follow-up, the patient had stable renal function with a serum creatinine of 2.5 mg/dL (GFR of 23.4 mL/min/1.73m2). We recommend that the BK virus be considered as a cause of renal dysfunction in heart transplant recipients, with the aim of detecting its replication in time to reduce immunosuppressive therapy before irreversible compromise of renal function may manifest.

Total nephroureterocystectomy and urethrectomy due to urothelial carcinoma associated with the BK polyomavirus infection after kidney transplantation: a case report with literature review

Background

BK polyomavirus (BKPyV) infection after kidney transplantation is an important cause of graft failure among kidney transplant recipient and may cause malignant tumor, although the association between BKPyV infection and malignant tumor has been controversial yet.

Case presentation

We report a case of a 39-year-old-male kidney transplantation (KTx) recipient with urine BKPyV replication who developed a graft pelvic tumor with the positive Simian virus 40 large T antigen (SV40 TAg). The patients received a living-related KTx from his 65-year-old mother. A protocol biopsy at 14 months after KTx showed BKPyV-associated nephropathy. Therefore, the dose of immunosuppressants was reduced, resulting in improved BKPyV viremia, but viruria persisted. About 117 months after KTx, urine cytology showed atypical cells suspicious for malignancy. Cystoscopy revealed a tumor on the neck of the bladder. Transurethral resection of the bladder tumor (TUR-BT) was performed; however, the diagnosis of malignancy was not confirmed at that time. Six months after the TUR-BT, urine cytology showed atypical cells definite for malignancy. Computed tomography and retrograde pyelography showed no evidence of urinary tract tumor and metastasis. Subsequently, total nephroureterocystectomy and urethrectomy were performed. Histological examination of the graft ureter revealed a high-grade urothelial carcinoma, with glandular differentiation, pT1. Immunohistochemically, the tumor showed positivities for SV40 TAg and p53, along with increased Ki67 labeling cells were increased. By contrast, nonneoplastic cells were negative for SV40 TAg. At the time of writing the present manuscript, the patient is free from recurrence or residual tumor and being closely monitored without additional therapy, 32 months after the surgery.

Conclusion

The relationship between BKPyV infection after KTx and bladder carcinogenesis remains to be elucidated. However, when the KTx recipients who continue to have BKPyV infection for a long time are treated, the possibility of risk factors for renourinary carcinoma should always be carefully considered.